C2

C2 or a derivative (C-2, C², etc.) may refer to:

Mathematics and physics

• C₂, one of the common notations for the cyclic group of order 2
• C² differentiability class
• c² the square of the speed of light (in the mass–energy equivalence formula)

Biology

• C2 domain, a protein structural domain
• C2 regulatory sequence for the insulin gene
• Apolipoprotein C2, a human apolipoprotein
• In human anatomy, C2 may refer to:
  • Cervical vertebra 2, the axis, one of the cervical vertebrae of the vertebral column
  • Cervical spinal nerve 2
• Chlorophyll c2, a form of chlorophyll
• Complement component 2
• Procyanidin C2, a plant phenolic compound
• Prodelphinidin C2, a plant phenolic compound
• Vitamin C2, a name sometimes used for Choline
• the ATC code for Antihypertensives, a subgroup of the Anatomical Therapeutic Chemical Classification System

Chemistry

• C₂, Diatomic carbon, a molecule made of two carbon atoms
• C2=, ethylene, a two carbon alkene

Codes or abbreviations

C2 may be a code or abbreviation for:

• C² Aquarii, a star
• C² Centauri, a star
• C2 (Code Geass), an anime character
• C2 Education, a K-12 tutoring and test preparation provider
• C2 error, a read error of a compact disc
• C2 explosive, a form of plastic explosive
• C2 (protocol), a 1985 Commodore file transfer protocol
• C2 pylon, a type of high voltage pylon
• C2 (radio), a Welsh language music show on BBC Radio Cymru
• C2 radio class, a class in FM broadcasting in America
• C2 (classification), a para-cycling classification
• Group C2, the secondary class of Group C sports car racing
• BRDC C2 Championship, a short lived sports car racing series which ran from 1988 to 1990
• Nimrod NRA/C2, a 1982 Group C racing car
• C2, an international standard paper size defined in ISO 216 (458×648 mm)
• C2, a level in the Common European Framework of Reference for Languages
• C2, the NRS social grade between C1 and D
• C2, a computer security class, defined in the Trusted Computer System Evaluation Criteria
• Cryptomeria cipher, a cipher used in digital rights management
• Command and control, the exercise of authority by a commanding officer over military forces in the accomplishment of a mission
• Air Luxor IATA airline code
• C2 Pictures, a film company related to Carolco Pictures
• Bill C-2 from Canadian law
• C2, or C₂ a note-octave in music, aka Low C

Transportation and space

• C2 class Melbourne tram
• Bavarian C II (Ostbahn), an 1862 German steam locomotive
• Bavarian C II.1, an 1857 German steam locomotive
• Bavarian C II.2, an 1861 German steam locomotive
• Chevrolet Corvette (C2), the generation of the Chevrolet Corvette produced between 1962 and 1967
• Citroën C2, a car produced by Citroën in 2004
• Cluster II (spacecraft), an ESA space mission
• GNR Class C2, a British 4-4-2 steam locomotive
• Kawasaki C2, a bike
• London Buses route C2
• LB&SCR C2 class, an 1893 British 0-6-0 steam locomotive
• Circumferential Road 2 or C-2, an arterial road of Manila, Philippines
• Saf-T-Liner C2, a school bus built by Thomas Built Buses
• Saturn C-2, a 1960 conceptual American launch vehicle
• Type C2 ship, a type of all-purpose cargo ship
• C2 (yacht), a luxury motor yacht

Military and aviation

• C2A1, Squad Automatic Weapon variant of the FN FAL formerly in Canadian Service
• C-2 Greyhound, the Grumman cargo aircraft of the United States Navy
• ACAZ C.2, a Belgian prototype fighter aircraft of the 1920s
• AEG C.II, a German World War II armed reconnaissance aircraft
• AGO C.II, a German reconnaissance biplane of World War I
• Cierva C.2, a 1921 Spanish experimental autogyro
• DFW C.II, a World War I German reconnaissance aircraft
• Fokker C-2, the American military version of the Fokker F.VII aircraft
• HMS C2, a British C class submarine of the Royal Navy
• Kawasaki C-2, a military transport aircraft
• LFG Roland C.II, a 1915 advanced German reconnaissance aircraft
• LVG C.II, a 1910s German two-seat reconnaissance biplane
• USS C-2 (SS-13), a C-class submarine of the United States Navy
• USS Charleston (C-2), a protected cruiser of the United States Navy
• A military term for Command and control
• C-2 (poison), developed in the Poison laboratory of the Soviet secret services

Other

• C2, UEFA Cup Winners' Cup in football, later merged with UEFA Cup (now UEFA Europa League)
• C2 Pictures, a film studio
• C-2 visa, a nonimmigrant visa which allows individuals to travel to and from the headquarters of the United Nations
• Coca-Cola C2, a soft drink launched by The Coca-Cola Company in 2004
• C2.com or WikiWikiWeb, the first user-editable website

See also

• CO2
• CII (disambiguation)